Disclosed herein are a method and a system for forming an air layer over a portion of an engineered surface, wherein the air layer is formed with a reduced flux and preferentially steering gas away from, or toward, a specific location by way of a hydrophobic surface, a hydrophilic surface, and/or a structured surface. Moreover, disclosed are a method and a system for recovering or separating a portion of the gas or other fluid layer.

A watercraft system including one or more air passageways and/or one or more water passageways is provided. The air passageways may extend from an upper surface of the watercraft, through the body of the watercraft, to an underneath surface of the watercraft. The water passageways may extend from an underneath forward or side portion on the watercraft, through the body of the watercraft, to a rear portion of the watercraft. The air and/or water passageways may be constricting from the inlets to the outlets so that the air and/or water is accelerated through the passageways during use of the craft. In this way, the release of the accelerated air and/or water decreases the craft's drag and provides the craft a forward thrust.

A watercraft system including one or more air passageways and/or one or more water passageways is provided. The air passageways may extend from an upper surface of the watercraft, through the body of the watercraft, to an underneath surface of the watercraft. The water passageways may extend from an underneath forward or side portion on the watercraft, through the body of the watercraft, to a rear portion of the watercraft. The air and/or water passageways may be constricting from the inlets to the outlets so that the air and/or water is accelerated through the passageways during use of the craft. In this way, the release of the accelerated air and/or water decreases the craft's drag and provides the craft a forward thrust.

The present invention relates to structured, gas-holding surfaces for improving the friction-reducing properties of gas layers held under a liquid and for the simultaneous suppression of turbulence. The present invention furthermore relates to a device comprising this structured, gas-holding surface and to the use of this structured, gas-holding surface.

The present invention relates to structured, gas-holding surfaces for improving the friction-reducing properties of gas layers held under a liquid and for the simultaneous suppression of turbulence. The present invention furthermore relates to a device comprising this structured, gas-holding surface and to the use of this structured, gas-holding surface.

An air supply apparatus for a ship is described. The air supply apparatus includes a fuel cell and an air lubrication device for resistance reduction of the ship. An exhaust gas outlet of the fuel cell is connected with the air lubrication device via an exhaust gas line for supplying exhaust gas to the air lubrication device. Further, a ship comprising an air supply apparatus according to any embodiments described herein as well as a method of supplying air to an air lubrication device of a ship are described.

An air supply apparatus for a ship is described. The air supply apparatus includes a fuel cell and an air lubrication device for resistance reduction of the ship. An exhaust gas outlet of the fuel cell is connected with the air lubrication device via an exhaust gas line for supplying exhaust gas to the air lubrication device. Further, a ship comprising an air supply apparatus according to any embodiments described herein as well as a method of supplying air to an air lubrication device of a ship are described.

A marine vessel hull, and marine vessels comprising at least one such hull, comprising a non-entrapment hull having at least one longitudinally vented transverse step, each longitudinally vented transverse step comprising a transverse step, and one or more longitudinal steps extending forward therefrom. Each longitudinal step portion has a cross-sectional profile defining a cutout into the hull relative to a line defined by a deadrise angle of the hull. The cutout defines a vertical rise starting from the line defined by the deadrise angle and a run tilted outwardly upward at a non-horizontal angle less than the deadrise angle and that extends to an intersection with the line defined by the deadrise angle.

A marine vessel hull, and marine vessels comprising at least one such hull, comprising a non-entrapment hull having at least one longitudinally vented transverse step, each longitudinally vented transverse step comprising a transverse step, and one or more longitudinal steps extending forward therefrom. Each longitudinal step portion has a cross-sectional profile defining a cutout into the hull relative to a line defined by a deadrise angle of the hull. The cutout defines a vertical rise starting from the line defined by the deadrise angle and a run tilted outwardly upward at a non-horizontal angle less than the deadrise angle and that extends to an intersection with the line defined by the deadrise angle.

A marine vessel (100) comprising: propulsion means (118, 134); a hull section (102); a body section (104) connected to said hull section via at least one stanchion (106, 108, 110, 112); and the body section and the hull section being movable relative to each other via said at least one stanchion.